1. Field of the Invention
The present invention relates to systems for handling canisters carrying product for treatment or processing, for example, systems for handling canisters in which monomer is converted to flocculant polymer as by exposure to ionizing radiation.
2. Description of the Prior Art
In the prior art, canisters lined with plastic bags receive a liquid monomer and are carried into a radiation chamber where the monomer is subjected to ionizing radiation to polymerize the monomer and form a solid polymer log with a rubber-like consistency which can be subsequently dissolved and used for various purposes. The canisters containing the polymerized material are removed from the radiation chamber and stored after which the polymerized material with the liner bag is then dumped from the canister for packing or further processing, and the canisters are cycled back for reuse as containers for receiving and processing additional monomer.
The canisters, after filling with the monomer, are transported in vertical carriers or racks which have rollers attached to the upper ends and supporting the carriers on overhead rails so that the carriers may be pushed to various processing stations. The prior art canisters are generally vertically oriented cylindrical plastic containers with an open top, and the carriers include a pair of vertically-extending horizontally arcuate members having vertically-spaced disc-like shelves attached therebetween with one side being open for receiving the containers on the shelves. A spring biased chain is secured over the open side of the carrier to retain the containers therein and to prevent their falling from the carrier during processing. After polymerization, the containers are removed from the carrier and the polymerized material dumped by manually inverting the containers.
The prior art canister handling methods are relatively costly in requiring manpower to lift and invert each canister to dump the polyermized material from the canisters. Also, the manual effort required to remove the logs of polymerized material often resulted in physiological stress causing higher than normal rates of sick leave. The spring biased chains holding the prior art canisters in the carriers are subject to breaking and to catching on objects or clothing while the carriers are being handled or rotated.